Telomere length is being analyzed as a marker for age-related diseases in the largest and most diverse study of aging to date. This genome project, the Genetic Epidemiology of Adult Health and Aging (GERA), aims to increase understanding of the genetic basis of a range of questions.

Funded by the National Institutes of Health, the project included a large-scale genotyping project that integrated longitudinal clinical and health data. After adjusting for a range of demographic and behavioral factors that affect telomere length (age, sex, race, education, physical activity, body mass index, smoking and alcohol consumption), individuals with the shortest telomeres were significantly associated with increased mortality.

"We found that people whose telomeres were in the shortest 10 percent were about 23 percent more likely to die within three years of their telomeres being measured, compared with people with longer telomeres," said lead study author Katherine Schaeffer, director of the Kazer Permanente Genes, Environment and Health Research Program.

The initial phase of the Kizer Health/UCSF Geraldine study measured telomere length in saliva samples from more than 100,000 people in California with an average age of 63 and analyzed information about their historical health obtained from health surveys and electronic medical records.

Large cohort study of 100,000 people demonstrates the importance of telomere length and health and provides a basis for continued research into the link between telomere biology and longevity.